Internal combustion engines



April 16, 1963 A. c. SAMFIETRO INTERNAL COMBUSTION. ENGINES 5 Sheets-Sheet 1 Filed Dec. 5, 1960 l/VVE/WDR BY J ,f v

ATTORNE) April 1963 A. c. SAMPIETRO 3,085,392

INTERNAL COMBUSTION ENGINES Filed Dec. 5. 1960 5 Sheets-Sheet 2 I l m a g} 1);

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d no ;1 8 N I ATTORNEY April 16, 1963 ,A.- c. SAMPlETRO INTERNAL COlVIBUST TION ENGINES 5 Sheets-Sheet 3 Filed Dec. 5, 1960 IIyI/ENTOR ATTORNEY P 1963 A. c. SAMPIETRO 3,085,392

INTERNAL COMBUSTION ENGINES Filed Dec. 5, 1960 s Sheets-Sheet 4 to m to l/EA TUR BY p/ M MVM A TTORNE Y April 1963 A. c. SAMF'IETRO 3,085,392

INTERNAL COMBUSTION ENGINES Filed Dec. 5, 1960 5 Sheets-Sheet 5 INVE/V TOR mew ATTORNEY 3,085,392 INTERNAL COMBUSTION ENGINES Achilles C. Sampietro, 286 Puritan, Birmingham, Mich. Filed Dec. 5, 1960, Ser. No. 73,580 Claims priority, application Great Britain Dec. 3, 1959 8 Claims. (Cl. 60-19) This invention relates to internal combustion engines of the type comprising a crankshaft and at least one driving unit therefor comprising a working cylinder with a working piston therein.

The proportions of the cylinders of internal combustion engines should ideally satisfy the two requirements of good thermal efiiciency and good mechanical eiiiciency. These requirements are, however, mutually contradictory; high thermal efiiciency demands a compact combustion chamber to minimise heat losses, and Where high oompressive ratios are used the piston stroke should be larger than the cylinder bore diameter, whereas for high mechanical efficiency the bore diameter should be larger than the piston stroke.

It has hitherto been necessary to compromise between maximum thermal efiiciency and maximum mechanical efficiency. The object of the present invention is to provide an engine wherein the said requirements are met independently of one another so that the thermal and mechanical efficiencies can both be improved with respect to conventional engines.

In accordance with the invention, in an engine of the type specified above, means are provided for transmitting the working thrust of the Working piston to the crankshaft through the intermediary of the liquid acting on an auxiliary piston drivably connected to the crankshaft and movable in an auxiliary cylinder. In this Way the functions of converting heat energy into mechanical energy and of converting this mechanical energy into rotational energy or torque are performed separately by the working cylinder and piston and by the auxiliary cylinder and piston respectively, and the dimensions of each cylinder can be selected and so related to the stroke of its associated piston as to fulfill the required function with maximum efiiciency.

An embodiment of the invention is illustrated in the drawings which illustrate an engine in accordance with the invention having three working cylinders each containing two opposed cylinders and in which two units are associated with the crankshaft for imparting rotation to it, the units being associated respectively with one of each of the pistons in the three working cylinders.

FIGURE 1 shows the three working cylinders and associated parts, and FIGURE 2 shows the units associated with the crankshaft,

FIGURE 3 shows an exhaust driven turbine which may be incorporated in the engine illustrated in FIG- URES 1 and 2,

FIGURES 4 and 5 illustrate a modification of FIG- URE 1 in which a single exhaust driven turbo compressor is employed, and

FIGURES 6 and 7 illustrate a modification of the arrangement shown in FIGURES 4 and 5.

Referring to the drawings, the engine comprises three similar driving units (FIG. 1) indicated respectively by the letters A, B and C. The driving unit A will be described in detail. The other two units have applied to them reference numerals which correspond to those used in describing the one unit in detail (unit A) but have single and double indices respectively. The driving unit A comprises a working cylinder 1 with a pair of opposed working pistons 2 and 3 therein. The pistons have piston rods 4 and 5 respectively Which are connected to ram pistons 6 and 7 which are movable axially in ram asssssz 3Q Patented Apr. 16, 1963 cylinders 8 and 9. The spaces in the cylinder 8 at the sides of the piston 6 have ports which are connected to pipes 10 and 11, and similarly the spaces at the sides of the piston 7 have ports connected to pipes 12 and 13.

The engine is provided with three exhaust driven turbo compressors 14, 14', 14". The turbo-compressor 14 supplies scavenging and fuel air to cylinder 1, through a pipe 15 and port 16 and the cylinder 1 is provided with an exhaust port 17 connected by a pipe 18 to the driving side of the turbo-compressor 14', which is thus driven by the exhaust gas from cylinder 1. The turbo-compressor 14' has its output side connected by a pipe 15 to a port 16' in the cylinder 1 which has an exhaust port 17' connected by a pipe 18 to the driving side of turbo-compressor 14", the output side of which is connected by a pipe 15" to an internal port 16" in the working cylinder 1", which has an exhaust port 17" connected by a pipe 18" to the driving side of turbo-compressor 14.

Referring to FIGURE 2, there are associated with the crankshaft 20 two units D and E each comprising three sets of auxiliary cylinders and pistons. The units D will be described in detail, the reference numerals used for the unit E are similar to those used for the one described in detail, but with the addition of the letter a.

The unit D comprises a casing 21 with three auxiliary cylinders 22, 23, 24 projecting radially inward therefrom, the cylinders being uniformly spaced around the crankshaft 20. The casing 21 is formed with three ports with which are associated respectively the pipes 10, 10' and 10 of FIGURE 1. The cylinders 22, 23 and 24 contain pistons 25, 26, 27 which are cup-shaped, having cylindrical flanges which are directed radially inwards and project into annular guide recesses formed by re-entrant parts 28, 29 and 30 of the cylinder Walls. These recesses are connected to the pipes 11,11, 11" of FIGURE 1. Thus, the sides of the pistons 25, 26, 27 of unit D are connected to the sides of the pistons 6, 6 and 6" of FIGURE 1. The sides of the pistons 25a, 26a, 27a of unit E are similarly connected to the sides of the pistons 7, 7' and 7" in FIGURE 1. The pistons 25, 26 and 27 are formed with arcuate recesses 30, 31 and 32 which serve as guides for arcuate end pieces 33, 34 and 35 on the radially outer ends of piston rods 36, 37 and 38, the inner ends of which are formed with arcuate end pieces 39, 40 and 41 which cooperate with one of the cranks 45 of the crankshaft 20, suitable guide means being provided if desired for maintaining the end pieces 39, 40 and 41 in sliding engagement with the crank. Unit B cooperates with another crank 45a of the crankshaft 20 and can be moved angularly about the centre line of crankshaft 20 through the medium of the lever mechanism 42, 43.

The driving units A, B and C are provided with fuel injectors indicated at 44, 44' and 44" and operate in a suitably timed sequence. The spaces in the ram cylinders 8, 8' and 8" above the ram pistons in FIGURE 1, the pipes 10, 10 and 10" and the spaces on the radially outer sides of the pistons 25, 26, 27 of unit D are filled with liquid e.g. oil so that the upward movement of say the piston 6 results in a radially inward movement of piston 25, the upward movement of ram piston 6 results in a radially inward movement of auxiliary piston 26, and the upward movement of ram piston 6 results in a radially inward movement of auxiliary piston 27. The spaces on the radially inward sides of the flanges of the pistons 25, 26, 27, the pipes 11, 11' and 11" and the spaces at the lower sides of ram pistons 6, 6 and 6" are also filled with liquid.

Similarly, the spaces in the ram cylinders 9, 9 and 9" in FIGURE 1 below the ram pistons 7, 7' and 7", the pipes 12, 12' and 12" and the spaces on the radially outer sides of the pistons 25a, 26a and 27a of uni-t E are filled with liquid, and the spaces above the ram pistons 7, 7' and 7", the pipes 13, 13' and 13" and the spaces on the radial inner sides of the pistons 25a, 26a and 27a are also filled with liquid.

In operation, the effect of the liquid in the various spaces and pipes as above described is that the movements of the upper ram pistons 6, 6 and 6" and the lower ram pistons 7, 7' and 7" are transmitted hydraulically to and cause corresponding movements of the auxiliary pistons 25, 26, 27 and 25a, 26a, 27a, the relative length of the strokes of the ram pistons of the one hand and of the auxiliary pistons on the other hand being determined by the bore diameters of the ram cylinders and of the auxiliary cylinders. It will be clear that these diameters can be selected so that the driving units A, B and C have good thermal efficiencies, the piston stroke being longer than the cylinder bore diameter, whilst due to the transmission of the working thrust of the working pistons 2, 2' and 2" and 3, 3', 3" being effected hydraulically the transmission of power to the crankshaft is also effected with high mechanical efiiciency, the bore diameters of the auxiliary cylinders being longer than the working strokes of the auxiliary pistons 25, 26, 27 and a, 26a and 27a.

It will further be apparent that the working pistons of the driving units A, B and C are not subject to side thrust as is the case in normal engines where the pistons drive directly on to the crank shaft, and that the side thrust on the auxiliary pistons of units D and E can be kept small due to these pistons having relatively short strokes as compared with the strokes of the working pistons, and comparatively long connecting rods 36, 37, 38 and 3&1, 37a, 38a. Further, the auxiliary pistons are efficiently lubricated due to the continual presence of large quantities of oil on both sides of them.

Angular movement of the unit E relative to the unit D serves to vary the relative phase of the working pistons 2, 2', 2 on the one hand and the working pistons 3, 3, 3" on the other hand, thereby enabling the compression ratio to be varied. If the exhaust port lead is increased more energy is available to drive the exhaust driven turbo compressors 14, '14, 1'4 so that the mass flow of air is increased and the quantity of fuel that can be burnt during each working cycle of the driving A, B and C can then also be increased, with an increase in the power developed. This provides for high efficiency at partial ioading of the engine and of high specific power at full load without the danger of incomplete combustion of fuel.

In a specific example, the bore of the working cylinders may have a diameter of five inches, the combined capacity of the three working cylinders being 354 cubic inches. The stroke of the working pistons may be six inches, as compared with a working stroke of say only 1.5 inches for the auxiliary piston-s.

The engine ab eve-described with reference to FIGURES 1 and 2 is intended for use with very dense charges, as is permissible since no limitation is imposed by the usual problems of connecting rod and crankshaft bearings encountered in conventional engines. With such dense charges the energy in the exhaust gases from the working cylinders will be more than is required to drive the turbo compressors 14, 14' and 14". FIGURE 3 illustrates a means of using the excess energy to assist in the driving of the crankshaft 20. The exhaust pipes 47, 47 and 4 of the turbo compressors 14, 14' and 14 are connected to the driving side of a turbine 43, the rotor 4-9 of which is drivably connected via bevel gearing 50, 51 to the crankshaft 20 (or to a shaft drivably connected thereto).

The additional drive provided by the turbine 48 is of particular importance when the compression ratio is reduced, the opening of the exhaust ports of the working cylinders 1, 2 and 3 being simultaneously advanced. Part of the increased exhaust gas energy is then used to increase the speed of the turbo compressors 14, 14' and 14", thereby increasing the density of the charge and the total mass flow, and the other part of the increased energy is used in the turbine 48, so that the engine has good efliciency both at port load and full load.

FIGURES 4 and 5 show a modification of the engine illustrated in FIGURES l to 3 in which a single turbo compressor is used instead of the turbo compressors 14, 14' and 14". The exhaust pipes 18, 18' and 18 of the working cylinders (FIG. 1) are connected to respective compartments of the turbine scroll 52, the said compartments being separated from one another so as to prevent the exhaust from one working cylinder blowing back into another working cylinder, as is necessary in multi-cyl-inder engines with high supercharging and large overlapping of the exhaust periods of the various cylinders. The bladed turbine driving rotor 53, only some blades 54 of which are shown, is drivably connected by shaft 55 to a sun gear 56 which is in mesh with planet gears 57 mounted on a planet carrier 58 and in mesh with an annulus gear 59, drivably connected to the bladed driven rotor 60 of the compressor. The compressor outlet is connected by pipe 61 to the inlet ports 16, 16 and 16" of the working cylinders 1, 1' and 1" respectively. The planet carrier 53 is drivably connected via a shaft 62 and by gearing not shown to the crankshaft 20 of the engine, the planetary gearing 56, 57, 58, 59' forming with the rotor 53 and shaft 55 a differential drive for the rotor 60 such that the speed of rotor 60 increases and decreases as the 'load on the crankshaft 20 increases and decreases. For any given speed of the driving rotor 53, maximum speed of rotor 60 is obtained when the crankshaft 20 is stationary. Thus the engine tends to maintain constant power output regardless of engine speed, or to increase the output torque when the engine speed drops. The shaft 62 may be drivably connected to the crank-shaft 26 electrically or hydraulically instead of by the mechanical means described.

In the modification illustrated in FIGURES 6 and 7, in order to facilitate starting, or to improve throttle re sponse, the turbine scroll 52 has one (or more) auxiliary compartment which is used as a combustion chamber and to which compressed air and fuel are supplied, the air being supplied in the embodiment illustrated, from a bottle 63 which is kept charged by a compressor driven by the engine. In large units a separate compressor may be used instead of the bottle 63. The air flowing firom the bottle 63 through pipe 72 is caused, on its way to the said auxiliary compartment, to drive a turbine rotor 64 which drives a fuel rotor 65 by which fuel is fed from a tank 73 to the auxiliary compartment via a nozzle 66 with which is associated an electrical igniter 74 in circuit with a high tension generator 67 which is under the control of a time switch and a main switch 69 in series with a battery 70. The time switch comprises a bi-metall-ic blade 68 and a heating coil 68' therefor.

At starting, the main switch 69 is closed, causing current to be fed to the generator 67 and also causing opening of a solenoid-operated valve 75 in the outlet pipe 72 of the compressed air bottle 63, so that fuel and air are supplied to the auxiliary compartment and the fuel is burnt therein, thereby starting and accelerating the compressor which then supplies sufficient air to scavenge the working cylinders during the starting or accelerating period.

After a predetermined time the bi-metallic switch opens and the supply of fuel and air to the turbo compressor ceases. In order toprotect the turbo compressor from overheating the main switch 69 should be opened when the bi-metal-lic switch opens and be kept open for a suitable period of time before being closed again.

Means such as one or more pumps may be provided for keeping the hydraulic systems fi-lled, and the pressure of the oil or other liquid in these systems may be arranged to be controlled by the load on the engine.

I claim:

1. An internal combustion engine comprising: at least one Working cylinder; opposed working pistons in said cylinder; hydraulic rams drivably connectedone to each of said working pistons; ram cylinders each enclosing one of said hydraulic rams; a crankshaft; at least two auxiliary hydraulic cylinders positioned about the crankshaft and being angularly adjustable relative to one another; double-acting auxiliary hydraulic pistons enclosed one in each of said auxiliary hydraulic cylinders and each drivably connected to said crankshaft; separate conduit means interconnecting each of said ram cylinders and corresponding ones of said auxiliary hydraulic cylinders, said ram cylinders, said auxiliary hydraulic cylinders and said conduit means being charged with hydraulic liquid; and means for adjusting the angular position of said auxiliary hydraulic cylinders about the crankshaft relative to one another whereby the relative timing of movements of the opposed working pistons may be altered thus altering the compression ratio and port timings of the Working cylinder.

2. An internal combustion engine according to claim 1, and also including, at least one turbine arranged to be riven by exhaust gas from said working cylinder; at least one air compressor; and means drivably interconnecting said compressor and said turbine, said compressor being arranged to supply scavenging and fuel air to said working cylinder.

3. An internal combustion engine according to claim 2, wherein said compressor is a rotary compressor, and said means drivably interconnecting said compressor and said turbine are constituted by differential gearing also drivably connected to the crankshaft, said drivable interconnections being efiected in such manner that the speed of the compressor relative to the speed of the turbine increases as the angular speed of the crankshaft falls and vice versa.

4. An internal combustion engine according to claim 3, and also including a further turbine arranged to be driven by the exhaust gases of the Working cylinder or cylinders, and means drivably interconnecting said further turbine and the crankshaft so that said turbine may transmit drive to the crankshaft.

5. An internal combustion engine according to claim 3, and including means for driving said turbine independently of the supply of exhaust gases thereto, said independent driving means comprising a compartment in the turbine scroll serving as a combustion chamber and means for supplying fuel and combustion air to said chamber.

6. An internal combustion engine comprising: first, second and third driving units, each of said driving units including a working cylinder, a pair of opposed working pistons, a pair of hydraulic rams secured one to each of said Working pistons, and a pair of ram cylinders each enclosing one of said rams; a crankshaft; first and second groups of auxiliary hydraulic cylinders arranged'about said crankshaft, said second group being angularly adjustable about said crankshaft relative to said first group; means for angularly adjusting said second group relative to said first group; a double-acting axiliary hydraulic piston in each of said auxiliary hydraulic cylinder, said auxiliary hydraulic pistons being drivably connected to said crankshaft; conduit means for connecting separately one of each of said pairs of ram cylinders to corresponding ones of said first group of auxiliary hydraulic cylinders; conduit means for connecting the other of each of said pairs of ram cylinders to corresponding ones of said second group of auxiliary hydraulic cylinders, said ram cylinders, said auxiliary hydraulic cylinders and said conduit means being charged with hydraulic liquid; a first turbo-compressor arranged to be driven by exhaust gases from the working cylinder of said first unit and arranged to supply scavenging and fuel air to the working cylinder of said second unit; a second turbo-compressor arranged to be driven by exhaust gases from the working cylinder of said second unit and arranged to supply scavenging and fuel air to the working cylinder of said third unit; a third turbo-compressor arranged to be driven by exhaust gases from the working cylinder of said second unit and to supply scavenging and fuel air to the Working cylinder of said unit; and a fuel injector in each of said Working cylinders.

7. An internal combustion engine comprising: first, second and third driving units, each of said driving units including a working cylinder, a pair of opposed working pistons, a pair of hydraulic rams secured one to each of said working pistons, and a pair of ram cylinders each enclosing one of said rams; a crankshaft; first and second groups of auxiliary hydraulic cylinders arranged about said crankshaft, said second group being angularly adjustable about said crankshaft relative to said first group; means for angularly adjusting said second group relative to said first group; a double-acting auxiliary hydraulic piston in each of said auxiliary hydraulic cylinders, said auxiliary hydraulic pistons being drivably connected to said crankshaft; conduit means for connecting separately one of each of said pairs of ram cylinders to corresponding ones of said first group of auxiliary hydraulic cylinders; conduit means for connecting the other of each of said pairs of ram cylinders to corresponding ones of said second group of auxiliary hydraulic cylinders, said ram cylinders, said auxiliary hydraulic cylinders and said conduit means being charged with hydraulic liquid; a turbo-compressor arranged to be driven by exhaust gases from said working cylinders, the turbine scroll of said turbo-compressor having first, second and third compartments, first, second and third exhaust conduit means interconnecting the exhaust ports of the working cylinders of said first, second and third driving units with said first, second and third compartments respectively of said turbine scroll; blower air conduit means interconnecting said compressor with the inlet ports of said working cylinders; differential gearing drivably interconnecting the compressor and the turbine of said turbo-compressor with said crankshaft in such manner that the speed of the compressor relative to the speed of the crankshaft falls and vice versa; and a fuel injector in each of said working cylinders.

8. An engine according to claim 7, wherein said turbocompressor is provided with means for supplying fuel and combustion air to the turbine, said means comprising an auxiliary compartment in the turbine scroll defining a combustion chamber, a compressed air bottle, a second compressor driven by the engine and arranged to supply compressed air to said compressed air bottle, conduit means connecting said bottle with the auxiliary compartment in said turbine scroll, a solenoid-operated valve in said conduit means, a fuel tank, a fuel injector in said conduit means leading to said auxiliary chamber, fuel conduit means interconnecting said fuel chamber with said fuel injector, a pump arranged for pumping fuel along said fuel conduit means to said injector, a second turbine arranged in said compressed air conduit means and drivably connected to said pump, an electrical fuel igniter arranged for cooperation with said injector, a high tension generator connected to said igniter, an elec trical battery connected in series with a main switch and a time switch for controlling said high tension generator and said solenoid-operated valve in said compressed air conduit means.

References Cited in the file of this patent UNITED STATES PATENTS 2,230,760 Pateras Pescara Feb. 4, 1941 2,623,384 Pigott Dec. 30, 1952 2,966,776 Taga Ian. 3, 19611 

1. AN INTERNAL COMBUSTION ENGINE COMPRISING: AT LEAST ONE WORKING CYLINDER; OPPOSED WORKING PISTONS IN SAID CYLINDER; HYDRAULIC RAMS DRIVABLY CONNECTED ONE TO EACH OF SAID WORKING PISTONS; RAM CYLINDERS EACH ENCLOSING ONE OF SAID HYDRAULIC RAMS; A CRANKSHAFT; AT LEAST TWO AUXILIARY HYDRAULIC CYLINDERS POSITIONED ABOUT THE CRANKSHAFT AND BEING ANGULARLY ADJUSTABLE RELATIVE TO ONE ANOTHER; DOUBLE-ACTING AUXILIARY HYDRAULIC PISTONS ENCLOSED ONE IN EACH OF SAID AUXILIARY HYDRAULIC CYLINDERS AND EACH DRIVABLY CONNECTED TO SAID CRANKSHAFT; SEPARATE CONDUIT MEANS INTERCONNECTING EACH OF SAID RAM CYLINDERS AND CORRESPONDING ONES OF SAID AUXILIARY HYDRAULIC CYLINDERS, SAID RAM CYLINDERS, SAID AUXILIARY HYDRAULIC CYLINDERS AND SAID CONDUIT MEANS BEING CHARGED WITH HYDRAULIC LIQUID; AND MEANS FOR ADJUSTING THE ANGULAR POSITION OF SAID AUXILIARY HYDRAULIC CYLINDERS ABOUT THE CRANKSHAFT RELATIVE TO ONE ANOTHER WHEREBY THE RELATIVE TIMING OF MOVEMENTS OF 